Child abuse and neglect are huge social problems affecting millions of infants, children, and adolescents in America. Several decades of research indicate that experiencing abuse or neglect is associated with substance abuse and a variety of other problems, including anxiety and depression;aggression and delinquency;cognitive delays and school achievement problems;problems with interpersonal relationships;and health problems. We know little about the role of maltreatment in increasing the risk for substance use, and in particular have much to learn about the mechanisms that may be responsible for this association. What is proposed is the first prospective, longitudinal study to examine the relationship of different child maltreatment experiences, carefully measured, to adolescent substance abuse with an emphasis on the role that psychobiological dysregulation and timing of puberty may play in this relationship. A second focal adolescent outcome of this study is high-risk sexual behavior, which is commonly associated with substance abuse. Also unique to this study will be analyses that examine trajectories of psychosocial functioning from early adolescence, during the pubertal transition, to mid/late adolescence in order to examine different patterns of resilience and maladaptation. This proposed study is a follow-up of maltreated (N=303) and comparison (N=151) adolescents (47% female) at ages 16 and 17, first assessed at approximately 11 years of age. The samples form balanced subsets of Latino, African-American, and Caucasian maltreated and comparison children residing in the inner-city of Los Angeles. Maltreated children were recruited through the Los Angeles County Department of Children and Family Services (LACDCFS). We recruited comparison children from the same neighborhoods as the LACDCFS sample. The sample of children has been measured on 3 occasions (known as Time 1, 2, and 3) at 1 to 1.5 year intervals in a cross sequential research design. A battery of measures on each occasion targets correlates and predictors of substance abuse and includes indicators of substance use;delinquency;competence in social and peer relationships;mental health and behavior problems (depression, anxiety, PTSD, aggression);psychobiological indictors of stress reactivity (salivary cortisol and salivary alpha amylase) and autonomic nervous system arousal (skin conductance, heart rate);indicators of cognitive abilities and school performance;and pubertal development. These same measures will be obtained at follow up, along with measures characterizing development in later phases of adolescence, including measures of the use and abuse of drugs and alcohol and measures of risky sexual behavior.